> if 320x480 frame then size_per_hour = 20.0 GB/hr * quality_factor/100
> >
> > if 640x480 frame then size_per_hour = 40.0 GB/hr * quality_factor/100
> DV is a flat ~12GB/hr. Now some have mentioned that as a shortcoming
> ("you don't get to select the quality") - but it's a feature to me.
> You can always degrade the image later :-)
If you want really know the amount of data you get, take a look at the
calcuation in the howto:
(width * height * framerate * quality ) / (200 * 1024)
That is for PAL (720x576) and NTSC (720x480) at the same quality of 80%
4090kB/s for the video for a BUZ. Audio is usually 172kb/s.
Every other card produces twice the amount of data for the video, unless
you play with the low_bitrate option in the zoran driver in the 2.6.x
Kernel
> > I think Steven would say that DV would offer better quality than the
> > MJPEG solution. DV is also a newer compression algorithm and as such
> > it had the opportunity to learn from MJPEG and correct some edge
> > conditions that reduce MJPEG's potential quality.
> Indeed. And the cost, today, is less. A Canopus ADVC100 and a cheap
> IEEE1394 card is less $$ than a MJPEG card and the raid-0 array needed
> to handle the I/O requirements. No need for a raid array since
> any disc these days (even external IEEE1394 drives on the same bus
> as the capture unit) can handle ~3.6MB/s.
BTW: 4 1/2 years ago I recorded full size with a single disk. But never
encoded it because it was SOOO slow ;)
I have never used raid arrays for recording video. But I have after had
a single disk in my system which I only use for recording videos.
> Another "feature" (which I've used fairly often) of DV is the fixed
> record size - for "NTSC" the DV records are 120000 bytes and "PAL
> 144000 bytes. You can use "dd" as a simple/crude editor (and with
> 'locked audio' - one of the benefits of the Canopus product line) you
> don't have to worry about slicing thru an audio sample.
Locked audio is designable. If the card's have the posibility to sync
audio and video. Than it is no problem. It is well done on the DC30 for
example.
BTW: The highest quality I can currently get. Is a digital satelite
receiver where I can download the recorded TS streams using ftp. The
most famous device in Germany/Austria/Swiss ist the Dreambox from Dream
Multimedia. Where you have Linux running on the receiver on a PPC-cpu :)
> cat cpuinfo
cpu : STB04xxx
clock : 252MHz
revision : 9.82 (pvr 4181 0952)
bogomips : 251.49
machine : IBM Redwood5
plb bus clock : 63MHz
---END---
Not the most powerfull machine, but works well for recording TS-Streams,
and playing back MP3 files when the computer is turned off.
auf hoffentlich bald,
Berni the Chaos of Woodquarter
Email: [EMAIL PROTECTED]
www: http://www.lysator.liu.se/~gz/bernhard
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